Volume 67, New Plymouth, 2005

Long-term analysis of price, productivity, and profitability trends in New
Zealand agricultureJ. COCKS and C. BROWN

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Much has been written and spoken over the years about
continually declining inflation adjusted commodity prices,
the volatility of the New Zealand dollar, and the
difficulties of competing against subsidized agricultural
sectors. While NZ agriculture has enjoyed good levels
of profitability in recent years these underlying forces
still remain and will continue to impact farm profitability.
Rising land prices and improved productivity of our
competitors are likely to erode NZ agriculture’s tr aditional
position as a low cost producer in the future. The
commonly cited responses to the forces outlined above
are 1) adding value to commodities, and 2) increasing
productivity. An earlier analysis showed that the NZ sheep
and beef sector, in particular, was experiencing
decreasing prices in real terms and farm productivity had
remained largely unchanged for fifty years. In contrast
to the data reviewed earlier, this paper shows that over
the last fifteen years the NZ agricultural industry has
been exhibiting just those responses required to combat
the forces above. New Zealand lamb prices have increased
in real terms since the late-1980s and in comparison with
international prices. Beef and dairy prices have also fallen
substantially less than the comparative international price,
however wool and wheat prices have fallen more than
the international price. In addition, there have been
significant increases in farm pr oductivity, most notably
lambing percentage, lamb carcass weights, and milksolids
production/ cow. The result has been a 57% increase in
dairy Earnings Before Inter est and Tax (EBIT) over the
past 5 years, compared with the previous half decade
(measured in real terms). Sheep farming has experienced
a 79% increase in EBIT over the same period. The
challenge and subject of significant debate which is
outside the scope of this paper is how NZ agriculture is
to remain at the forefront of global pastoral agriculture
as a low cost, innovative, and profitable sector.
Keywords: agricultural productivity, farm profitability,
product prices, New Zealand agriculture.

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A proud history
As we look forward and plan for the future of the
New Zealand Grassland Association (NZGA) you
have to be able to reflect on the foundation on
which this Association has been built. As we
enter our 75th year of existence we can reflect on
a very proud history well documented in 1989 by
Derek Woodfield and Deric Charlton.

Clover root weevil (Sitona lepidus) in New Zealand: the story so farJ.P.J. EERENS, S. HARDWICK, P.J. GERARD and B.E. WILLOUGHBY

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The rapid spread of clover root weevil (Sitona lepidus)
(CRW) since its introduction in the early 1990s,
threatens the competitive advantage of New Zealand’s
pastoral industry. When CRW was discovered, it had
already spr ead too far for containment. The insect’s
distribution currently covers the North Island and there
is no reason to prevent its spread ultimately throughout
NZ. With no competing species, CRW is more
damaging in NZ than in its native Europe. Clover root
weevil affects white clover nitrogen (N) fixation while
simultaneously reducing the clover content of pastures
thereby lowering total forage quality. Legume
germplasm was screened for resistance/tolerance and
while no resistance was discovered, vigorous growing
white c lover plants showed tolerance to CRW and gains
from selection for tolerance were achieved. Eliminating
remnant clover before pasture renovation or growing a
crop between grass stages reduces the resident CRW
population and improves clover re-establishment.
However, CRW can reinvade and potentially return to its
original density. Two candidate biological control agents
are being pursued for release later in 2005. Clover root
weevil’s impact on pastoral farming varies, partially due
to environmental variation, which dictates clover growth
and CRW development.
Keywords: clover root weevil, cultivar selection, life
cycle analysis, pasture management, Sitona lepidus

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Clover root weevil (CRW) has become a major pest of
white clover in pastures in much of the North Island. In
contemporary, intensively stocked pastures, high
volumes of nitrogen (N) cycling through the soil/plant/
animal system stimulate grass growth and reduce the
clover content of pastures. Clover root weevil imposes
further stresses on clovers. A range of white and red
clover germplasm was evaluated f or CRW tolerance from
2002-2005 on Waikato dairy and sheep/beef farms.
Results confirmed the importance of good agronomic
adaptation if clovers are to survive the additional stress
of CRW. Two recently released white clover cultivars
(Grasslands Kopu II and Tribute) were amongst the top
performing lines under dairy farm grazing. Under sheep/
beef grazing, spreading type red clovers also performed
well. A white c lover breeding line selected for tolerance
of plant-feeding nematodes was in the top group of clovers
at both sites. Reducing stresses on clovers from other
pasture pests will contribute to improved tolerance to
CRW. A glasshouse experiment showed that CRW larval
feeding can severely damage white clover nodules and
reduce N fixation. The plants have considerable capacity
to grow new nodules but this diverts energy away from
other growth processes. Our conclusions are that welladapted,
vigorous white clover cultivars are better able
to cope with the additional stress imposed by the root
weevil. Good pasture management and attention to
fertiliser requirements can improve clover survival under
root weevil herbivory. New generation red clovers show
considerable potential for weevil infested areas. Coselection
for tolerance/resistance to other major clover
pests e.g. clover flea and root nematodes will improve
plant performance under CRW stress.
Keywords: clover root weevil, nitrogen fixation, plant
breeding, red clover, white clover

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Breeding for improved resistance and tolerance to the
clover root-knot nematode, Meloidogyne trifoliophila,
and the clover cyst nematode, Heterodera trifolii , has
been successful in white c lover, Trifolium repens. White
clover lines developed from three independent breeding
programmes were established in field trials at Lincoln,
Palmerston North, Cambridge and Kerikeri. Plants were
established in areas either untreated or treated with
nematicide, so as to have contrasting pest loads on the
plant material and evaluated for up to 4 years. Plant vigour
was scored before each grazing at each site. Clover cyst
nematode cysts were counted twice in Palmerston North
and all nematodes were counted in stained roots on four
occasions in Cambridge.
Resistant lines from the clover cyst nematode
programme performed better than susceptible lines and
as well as most cultivars reflecting the high level of
resistance developed in this glasshouse-based
programme. This resistance was also reflected in the
generally lower number of cysts counted under resistant
lines from Palmerston North. The root-knot nematode
resistant material performed better than the susceptible
and as well as most cultivars. The tolerance selections,
developed under field conditions, performed as well as,
or better than the cultivars. The selections from the
breeding programmes have exhibited strong agronomic
potential across locations and years and the best material
has been crossed, with progeny being assessed in current
field trials.
Keywords: Heterodera trifolii, Meloidogyne trifoliophila,
nematode, pasture, resistance, tolerance, white
clover

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The establishment of new clover-based pastures takes a
full year and has two distinct components; seedling
emergence from sowing, and subsequent grazing
management. A Ministry of Agriculture and Forestry
(MAF) Sustainable Farming Fund (SFF) project to
investigate the causes of inconsistency of white clover
establishment concluded this came primarily from a lack
of knowledge of white clover in both sowing and grazing
management skills, and reflected how far modern farming
technology has moved away from clover-based systems
towards nitrogen (N)-boosted systems in recent years.
Typically, less than half the seed being sown emerges,
for both ryegrass and clover, although good results do
occur. A trial looking into seedbed conditions on a dairy
farm highlighted the importance of good seedbed
consolidation in order to accurately control sowing depth,
lifting white clover emergence by 50% and ryegrass by
25% using a roller drill. Consolidation did not affect
emergence using a triple disc drill, but it did improve
quality of sowing by reducing soil drag and spill by the
rear coulters causing excessive burial of the front coulters
rows. Differences in emergence were still evident in the
performance of the clover in the following summer with
14% clover in the areas that had been hard rolled compared
to 4% where it had not. In another trial on a hill soil of
lower N fertility status, the taking of hay crops in the
first summer, not a normally recommended practise,
enhanced clover establishment compared to rotational
grazing all year. The roles of clover, N fixation and quality
feed, are discussed in the context of how and where
clover may fit into modern farm systems.
Keywords: emergence, establishment, grazing
management, seedbed preparation, sowing methods,
white clover

Applying science as a tool for dairy farmersJ. SAVAGE and C. LEWIS

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Dairy Systems Monitoring (DSM) was developed out
of response from dairy farmers for a benchmarking tool
that made fair and equitable comparisons between farms.
This benchmarking system is used by the clients to
improve their productivity and profitability.
The dairy farm simulation model UDDER is used to
simulate the farm system. The input information is milk
production from fencepost, and monthly data from the
farm, including, areas, stock numbers, supplements,
crops and nitrogen (N). The model is then calibrated to
simulate the farms production, revised and validated
monthly.
There has been a successful uptake of this program.
Currently 50 farms are involved. Dairy Systems
Monitoring has generated change in the systems of
participating farmers. Dairy Systems Monitoring has
proven to be an effective tool to demonstrate the impact
of a range of new technologies on farm systems.
The tool is used on an ongoing basis to simulate and
compare different operating strategies. It has the ability
for clients to compare themselves to simular farms.
A key benchmark that is analysed is the feed harvested.
For every additional 1 tonne of dry matter (DM)
harvested, the gross margin (GM) increases by $339/ha.
The question this poses for participants is “how do we
harvest more pasture”? Is it by growing more pasture, or
improving management to harvest more of the existing
pasture growth?
Dairy Systems Monitoring is an effective extension
tool to highlight the impact of new technologies or
management practices on the client’s farm program.
Keywords: benchmarking, dairy farm programmes, feed
harvested, gross margins, UDDER model

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Over four dairy seasons (2000/2001 to 2003/2004) the
input of maize silage was evaluated at the Waimate West
Demonstration Farm. Two systems were evaluated with
Jersey cows: Control (3.8 cows/ha, no maize silage) and
High stocked (HS) Maize (5 cows/ha, up to 1.5 t dry
matter (DM)/cow/yr as maize silage). Both farmlets
received 190 (±5) kg nitrogen (N)/ha/yr in split
applications throughout the season, and calving
commenced on 9 July for both herds.
Only small differences between treatments in annual
milksolids (MS) yield/cow were recorded. The Control
herd averaged 310 kg MS/cow in 260 days compared
with 316 kg MS/cow in 277 days for the HS Maize
herd. The HS Maize herd produced 34% more MS/ha
than the Control herd, viz. 1566 and 1172 kg/ha/yr
respectively.
Milksolids response to the additional DM and higher
stocking rate (SR) on the HS Maize system averaged 80
g MS/kg extra DM consumed. The annual economic
farm surplus (EFS) averaged over 4 years for the
Control herd was $2784/ha and the HS Maize herd was
$2551/ha, however greater between year variation in
EFS was noted for the HS Maize system.
Incorporation of maize silage into a pasture-based
dairy system does increase production/ha, however the
profitability of the system will be more vulnerable to MS
payout and maize silage price than the traditional
pasture-based system.
Keywords: dairy, economic farm surplus, maize silage,
pasture production

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The aim of the Resource Efficient Dairying (RED) trial
is to measure the productivity, economic and
environmental effects of different feed inputs and
management processes on a dairy farm. This is a longterm
systems trial located at Scott Farm (Dexcel Research
Farm) established on 1st June 2001 and expected to
continue until 2006. Trial design was based on six systems
that have an allowance of up to 200 kg nitrogen (N)/ha
(excluding the low input treatment). They are: low input
(no N fertiliser, heifers grazed-on and 2.3 cows/ha);
control (3 cows/ha); standoff (3 cows/ha); low
supplement input (5 t dry matter (DM) maize silage/ha,
3.8 cows/ha); moderate supplement input (10 t DM maize
silage/ha; 5.2 cows/ha); and high supplement input (15 t
DM maize silage + 5 t soymeal/ha; 6.9 cows/ha). The
last two systems have irrigation available to boost pasture
production. All systems were designed to operate at a
common comparative stocking rate (CSR) of 85 kg
liveweight (LW)/t DM. Two seasons’ data have shown
that increasing the stocking rate (SR) by 1.5 cows/ha
from 3.8 to 5.3 cows/ha, plus extra feed, increased output
by 90 and 184 kg milksolids (MS)/total ha in the two
years, when the extra area required to supply the extra
feed is included in the calculation of kg MS/ha. However
the further increase to 6.9 cows/ha plus extra feed
produced less MS/total ha than the system stocked at 3.8
cows/ha. Calculations of economic farm surplus (EFS)
and return on assets (ROA) reveal that when the payout
is $3.50/kg MS the low input system is competitive
irrespective of land price ($18000 or $37000/ha) or
supplement cost (18 c or 24 c/kg DM). Conversely at a
higher payout of $4.50/kg MS the treatment
supplemented with 10 t maize silage DM/ha is competitive
over the range of land prices and supplement costs tested.
Keywords: dairy cows, economic evaluation, maize
silage, milksolids, nitrogen fertiliser, stocking rate

The practicality and profitability of feed inputs on the Stratford Demonstration
FarmG D PITMAN

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A four-herd dairy farm farmlet trial was carried out on
the Stratford Demonstration Farm in Central Taranaki
for four seasons (2001/2002 to 2004/2005). This trial
examined the profitability and practicality of different
feed input systems including on-farm forage cropping
and the use of new pastures. The farmlets included:
1. A self-contained control group moderately stocked
at 3.3 Jersey cows/ha.
2. A group with the same stocking rate (SR) but using
high quality silage made on the farmlet to allow
milking for a long lactation (280 days/cow) and
feed purchased to balance the winter feed budget
(MPF).
3. A group, high stocked at 4 Jersey cows/ha to allow
direct grazing of the grass by milking cows with
minimal supplements made but feed purchased
(grass silage and hay, maize silage, winter grazingoff)
to allow a moderate to long lactation length
(270 days/cow) and to balance the winter feed
budget (HPF).
4. A group also at the moderate SR and self-contained
but with 12% of the farmlet cropped with summer
turnips and Triticale cereal silage crops to increase
total feed production, as well as introduce the use of
higher quality pasture cultivars (crop).
Increased milk production was achieved by the
increased inputs with a response rate of 142 g milksolids
(MS)/kg dry matter (DM) from buying-in feed to extend
the lactation and 84 g MS/kg DM from buying-in feed to
run a higher SR. The cropping and regrassing system
also resulted in a 4.9% increase in MS production, but
crop yields were much lower than expected, significantly
affecting the results.
The MPF group with purchased feed to extend the
lactation produced the best economic result under the
costs and milk payouts used. The HPF group produced
the most variable and lowest economic result. The extra
milk production from this group was sufficient to cover
the extra feed costs but not the cost of running the extra
cows. The extra milk production on the cropping farmlet
covered the cost of the cropping and allowed a high level
of regrassing at no net cost, but minimal economic
benefit. The value of the new pastures in the system,
however, improved each season. Labour costs, feed
costs and milk payout are critical factors in the differing
economic results. These vary greatly from farm-to-farm, and year-to-year and differences here can change the
relative economics of each system.
Keywords: economic farm surplus, feed input systems,
milksolids production, profit

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A model of the New Zealand beef value chain, from
conception to export, was constructed. The model was
parameterised at the national level so that issues and
opportunities within the beef industry can be examined
at a high level by researchers and industry participants.
The model is capable of modelling changes in farm
practice, market situations and the industry structure. To
illustrate the integrative power and value of the model in
evaluating change within the beef sector, three scenarios
are presented and compared to the status quo: changes in
land price; wider use of beef semen in the dairy industry;
and introduction of a gene to improve net feed intake.
From the three scenarios presented, it is apparent that
land price dominates the ability of the NZ beef industry
to create value in the long-run. Although behaviour,
practices and technologies can contribute to overcoming
this factor, such changes will need to be substantive –
incremental improvements will not be sufficient. This
model provides the basis for facilitating debate on the
future of NZ’s beef industry and how to ensure long-run
profitability.
Keywords: beef industry, scenario evaluation, beef
systems, value chain model

Effect of the rate of potassium chloride on dairy production in TaranakiJ. D. MORTON, C.J. ROACH and A.H.C. ROBERTS

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Potassium chloride (KCl) was applied at 4 rates (0, 150,
450 and 1150 kg/ha) to pasture on closed 5 ha farmlets
over 3 years, and pasture and animal production and
animal health measured. Friesan, Jersey and Friesan x
Jersey cows were stocked at 3.2/ha on an Egmont
Allophanic soil near Hawera in South Taranaki. Average
soil potassium quick test (QTK) levels were 7, 8, 10 and
12 respectively from 0, 150, 450 and 1150 kg KCl/ha.
There was a small significant negative linear effect of
rate of KCl application on annual pasture dry matter
(DM) production averaged over three years (16864 –
18359 kg/ha). The average amount of silage conserved
(1369 – 2112 kg DM/ha) was consistently greater at the
highest rate of KCl. Increasing rate of KCl had no
significant effect on the nutritive value of grazed pasture
but resulted in increased K content of silage. There was
no significant effect of KCl on milksolids (MS)
production (1034 –1179 kg/ha/lactation) or reproductive
performance. There was a trend for the incidence of
clinical metabolic disorders (8-18%) to decrease with
increasing rate of KCl but this was not significant
because of the low number of cows in each herd. The
results from this trial suggest that soil QTK levels above
the target range for optimal pasture production of 7-10
on Allophanic soils are not associated with increased
dairy production and have no adverse effect on animal
health.
Keywords: calcium, dairy cows, hypocalcaemia,
hypomagnesaemia, magnesium, milksolids, pasture,
potassium, potassium chloride

More beef calves from the dairy industry: a surveyL. OLIVER and A. MCDERMOTT

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A telephone survey of dairy farmers, calf rearing farmers,
and finishing farmers was undertaken to discover
opinions regarding dairy-beef cattle and the barriers to
increasing the quality and quantity of dairy-beef cattle
produced by the dairy industry. A total of 158 farmers
were surveyed from throughout New Zealand. Dairy
farmers make the most critical decisions regarding the
genetic make-up of most cattle entering the NZ beef
industry. To ensur e these decisions benefit the beef
industry, there is a need for incentives to encourage dairy
farmers to use more beef genetics across their herds. The
survey results suggest a premium for dairy-beef calves
of $30-$50/calf above Friesian bull calf prices would be
an adequate incentive. Delivering this premium requires
a co-ordinated effort involving beef finishers, calf rearers,
dairy farmers and beef processors.
Keywords: beef finishers, calf rearers, dairy-beef cattle,
dairy farmers, incentives, industry co-ordination

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Although summer is a critical season for sheep
production on summer-wet hill country, little is known
about how high-performing farmers manage livestock
and pastures during this period. If their practices could
be captured and disseminated, it would provide the
opportunity for other farmer s to increase productivity.
The decisions made by a high-performing summer-wet
hill-country farmer over summer were investigated using
a single-case study design.
This study highlights the relative complexity of summer
management on hill country. Farmers must consider key
strategic decisions such as when to wean, when to sell,
what to sell, how many to sell, where to sell and at what
weight. In this study, the answer s to these questions
were found to be a function of the conditions (summerwet
versus summer-dry) under which one farms and the
amount of finishing country one has. Under summerwet
conditions, the need to control pasture quality dictates
important strategic decisions. To control pasture quality,
the case farmer runs a high stocking rate (SR), high
performance, later lambing system with a low sheep:cattle
ratio. This system, particularly with a low proportion of
finishing country, is not conducive to lamb finishing and
a store policy is a more profitable alternative. As such,
the case farmer’s focus over summer is on ensuring the
potential for high ovulation and conception rates in his
ewes and ewe hoggets rather than lamb finishing. This is
achieved by ensuring his ewes are in good condition
(2.7 condition score (CS)) with adequate feed (1400 kg
dry matter (DM)/ha) at flushing and his ewe hoggets
reach 41 kg live weight (LW) by May 1st. These nonnegotiable
targets are central to the farmer’s consistent
high performance. Minimisation of the distribution of
LW (or CS) a bout the mean of different sheep classes
through preferential feeding of younger, lighter and
thinner stock was also found to be a critical element.
To achieve high lamb growth rates, low priority stock
and older finishing cattle were used to ensure pastures
remained actively growing, of high quality and with low
levels of infective larvae. A late weaning date and a high
proportion of cattle and older stock were also important
in maintaining pasture quality on summer-wet hill country.
A critical feature of summer grazing management is area
allocation and the use of post-grazing residuals to achieve animal performance targets. Pasture monitoring, microbudgeting
and the use of this information in conjunction
with market related data, to help decide the appropriate
timing of stock sales was central to coping with
uncertainty and achieving pasture and animal targets.
Keywords: farmer decision making, grazing
management, sheep productivity

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The approach was to use the Whole Farm Model
(WFM) and Taranaki climate to compare a conventional,
twice-a-day milking farm system with variations of
once-a-day (OAD) milking and high-input systems.
The aim was to compare production, return on assets
(ROA) and risk as affected by climate and price
variability. Simulations were run over 9 different climate
years (1995/1996 – 2003/2004). The high-input system
had the highest production (1333 kg milksolids (MS)/
ha) and highest ROA (10.8%), with variability thereof
dampened by a feed buffer of higher quantity and quality
that existed because of higher pasture yields (15.8 t dry
matter (DM)/ha with 200 kg nitrogen (N)/ha vs. 13.5 t
DM/ha with 105 kg N/ha for the other two systems),
maize silage and grazing-off. The high-input system
was followed by the OAD and conventional systems in
terms of production (1068 and 975 kg MS/ha
respectively) and ROA (9.8% and 9.2% respectively).
Both OAD and conventional systems showed risk
values nominally lower than high-input, but both these
systems were more severely affected by climatic
var iability, which lowered the average return and
increased the risk relative to the return.
Keywords: climate var iability, high input farming,
once-a-day milking, return on assets

Impacts of intensive dairying on soil and pasture sustainability in TaranakiC.G. ROACH and J. D. MORTON

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The intensification of dairying can have adverse impacts
on the environment through diminished soil quality and
greater loss of nutrients to water bodies. Poor soil quality
can reduce the productivity and sustainability of pastoral
farming systems. The effects of increased stocking rate
(SR) (3, 4 and 5 cows/ha) and introducing a cut and
carry system on soil, pasture and water quality were
compared with a pasture fallow on an Egmont
Allophanic soil in South Taranaki over three years. Soil
nutrient and organic matter (OM) levels were not
affected by the treatments imposed and were maintained
in the ranges for adequate plant growth by the application
of fertiliser (grazing) or farm dairy effluent (cut and
carry). Macroporosity in the top 5 cm of soil was greater
for the fallow treatment (31-37%) than the other
treatments (cut and carry 20-25%; grazing 17-21%).
Treading damage as indicated by soil surface roughness
only increased with SR in one winter grazing when the
soil was saturated. The management treatments had no
significant effect on annual pasture production. Ryegrass
content significantly increased with grazing and higher
SRs and there was more dead material in the fallow
treatment. Pasture chloride (Cl), potassium (K), nitrogen
(N) and phosphorus (P) contents were significantly
lower in the fallow treatment and pasture K content
significantly lower in the cut and carry treatment than in
the grazing treatments. The leaching loss of calcium (Ca)
was significantly lower in the fallow treatment in 2003,
and in 2004, the rate of magnesium (Mg) leaching
increased in the grazing treatments. Nitrate-N leaching
losses were low (average 5 kg/ha/yr) but in the 2004
drainage season were significantly higher in the fallow
compared with the cut and carry and grazing treatments.
Overall it could be concluded that the more intensive
management had no adverse effect in the short term on
the sustainability and quality of soil, pasture and
groundwater.
Keywords: dairying, nutrient leaching, nutrients,
pasture, soil macroporosity, sustainability

Regrassing flood-damaged pasturesM.D. WILSON and I. VALENTINE

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On the night of February 14th 2004 the lower North
Island was hit with a storm system, which would cause
the biggest flood seen in the region for over 100 years.
The hardest hit areas include the Manawatu, Rangitikei,
Horowhenua, Wairarapa and Wanganui regions. In the
summer after the event, a survey was conducted of the
affected areas. Semi-structured interviews of 52
individual farmers focused on their farm operations, the
impact of the flood, and their regrassing strategies. The
interviews established the state of the pastures postflood
including depth and texture of silt deposit; water
levels and flow; duration of inundation; and soil surface
condition. The regrassing strategies included seedbed
preparation, sowing technique, fertilizer use and weed
control. Site measurements made were: pasture cover
and species content, and that soil profiles revealed
rooting depth and silt depth (if not cultivated). General
trends that emerged were that the more thoroughly a
seedbed was prepared the lower the risk of pasture
establishment failure. Nitrogen (N) applications of 75
kg/ha over the intervening period did not have a
significant effect but where deep sediment was
encountered two or three applications of N was reported
to produce feed and start inputting organic matter (OM).
The use of a roller drill increased the reliability of
establishment and was essential for the establishment of
pasture legumes. Double normal seeding rates (30-40
kg/ha) increased the reliability of success where the seed
was broadcast. Many farmers that had no sediment
reported perennial weed problems including couch,
creeping buttercup and a variety of thistles. Small scale
surface cultivation was reported to decrease drying time
dramatically in extremely wet areas.
Keywords: ground cover, pasture cultivars, pasture
establishment, seedbed preparation, weeds and pests

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New Zealand has had many changes in the dairy industry
during the last twenty years. As NZ dairy farming has
particular characteristics (e.g. differing ownership
structures, geographic areas) risk perception and
management strategies may differ significantly between
them. No studies have been undertaken regarding the
differences in perception of risk and risk management
strategies used by different gr oups of dairy farmer s. A
survey of 1000 NZ dairy farmers was conducted in 2004
and further analysed to address this need. In the survey
the dairy farmers were asked to assess their perception
of risk sources and the importance they attached to risk
management strategies. Using a 1 to 5 scale, mean scores
of both risk sources and management strategies were
compared (Z-test) by ownership structure and geographic
location. The differences in the perception of risk between
sharemilkers and owner-operators were mainly in the
sources categorised as “market” and “human”. “Changes
in land prices” was highly important for sharemilkers.
Differences of risk management strategies were noted in
the “financial” and “production” categories. The main
sources of risk perceived differently by farmers in the
North and South Islands were in the production side of
the business. Although farmer s from both islands were
similarly focused on controlling risk through production
management strategies, those from the South Island were
keener to use financial responses. In conclusion,
sharemilkers were more concerned with the changes of
prices of both inputs and outputs than owner-operators.
Sharemilkers were more production-orientated to manage
risk than farm owners, and they also were more focused
on off-farm income and debt management. Differences
in both the risk perception and the risk management
strategies used in each island are related to differences in
farm sizes and the developmental stage of the dairy sector
in each island.
Keywords: risk perception, risk management strategies,
sharemilkers

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The utilisation of whole-crop cereal silage, when fed on
pasture, is an unknown factor when assessing the
economics of whole-crop cereal silage in dairy farming
systems. This study aimed to document the utilisation of
whole-crop cereal silage and compare it to the utilisation
of pasture silage fed under the same conditions. Data
was collected from nine whole-crop cereal and two
pasture silage feeding events during the autumn and
spring of 2004. The concentration of silage fed in spring
(3.04 kg (dry matter) DM/m) was lower (P<0.001) than
that fed in autumn (4.59 kg DM/m). Residual silage left
after feeding (kg/m fed) was not significantly affected
by season or silage type. When expressed as a percentage
of that fed, utilisation was lower for whole-crop cereal
silage (80.6%) than for pasture silage (90.4%; P<0.032).
However, when silage utilisation (g/kg DM fed) and the
amount fed (kg DM) were compared, the utilisation of
the silage was positively related to the amount fed (r2 =
0.44; P<0.001) with utilisation of over 90% being
achieved when more than 4 kg DM/m was fed (measured
in 38% of the feeding events).
Keywords: dairy cows, pasture, silage, utilisation,
whole-crop cereal

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Improved productivity and utilisation of forages will be
central to maintaining business viability on high value
Tar anaki dairy land. Data from 712 plots in 119 trials
planted over ten years in Taranaki was analysed to
determine average yields and the impact of planting date
on yield. Six rural contractors who plant approx. 90% of
maize in Taranaki were surveyed to determine the
perceived factors most limiting maize yields in the
Taranaki. The overall average Taranaki maize silage dry
matter (DM) yield of all hybrids from the trialling
program over the past ten years was 20.5 t DM/ha and
the average harvest DM content was 33.8 %. Currently
commercially available hybrids yielded an average of
20 t DM/ha. Average maize silage yield/yr varied from a
high of 22 t DM/ha in 1999 to a low of 18.3 t DM/ha in
2004.
Planting between the 15th and 24th October gave the
greatest crop yield. Paddock selection seemed to be
driven by the need for pasture renovation rather than
paddocks being selected because they provide an ideal
growing environment for maize. Contractors suggested
shelter was a key consideration for increasing yields.
Keywords: cropping , maize silage , Taranaki

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Three experiments were conducted to compare
milksolids (MS) production from cows grazing similar
herbage allowances of timothy (Phleum pratense)/white
clover (Trifolium repens) and perennial ryegrass
(Lolium spp.) pastures. Two experiments were shortterm
(2 weeks), one in spring 2000 (Experiment 1) and
one in autumn 2001 (Experiment 2), and one longerterm
(12 weeks) irrigated trial in summer/autumn 2002
(Experiment 3). In Experiment 1, the yield of all milk
components; fat, protein, MS, casein and lactose, was
greater from timothy/white clover than ryegrass,
whereas in Experiment 2, the production of these
components from timothy/white clover was less than
from ryegrass. The protein content of timothy/white
clover was greater than ryegrass in spring (P<0.05) but
similar in autumn. In spring, acid detergent fibre (ADF)
and neutral detergent fibre (NDF) were similar but in
autumn they tended to be higher in timothy/white clover
than ryegrass, indicating poorer quality of timothy/white
clover relative to ryegrass in autumn. In spring and
autumn the digestibility and metabolisable energy (ME)
of the two pastures types were similar. In Exper iment 3
the pastures were irrigated. The experiment was a
crossover design with the cows grazing each of the
timothy/white clover and ryegrass pastures for two,
three-week periods. The yield of all milk components
was greater from Timothy/white clover than ryegrass.
Digestibility and ME were similar for the two pastures
but the timothy/white clover pastures had lower NDF
and higher water-soluble sugar content than ryegrass.
More cows were carried on the timothy/white clover
pasture and as a result MS production/ha was increased
by 30%. This research identifies an opportunity for
greater use of irrigated timothy/white clover pasture in
dairying systems not subjected to an Argentine Stem
Weevil (ASW) challenge.
Keywords: milksolids production, nutrient
composition, perennial ryegrass, timothy, white clover

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This study compared the yield and nutritive content of
conventional and leafy maize silage hybrids, and the
expected differences in milksolids (MS) production if
fed to cows. A range of conventional and leafy hybrids
were planted in paired strip trials (n=162) or small plot
trials (n=132) during spring 1999, 2000, 2001, 2002,
2003, and 2004 in all of the main maize silage growing
areas from Nor thland to Canterbury. Pair ed comparisons
of short, medium, and long maturity conventional and
leafy hybrids were made. On average, conventional
hybrids yielded 1824 kg DM/ha (9%) more than leafy
hybrids and had a marginally lower fibre digestibility
(0.6 percentage units). Modelling using the Cornell Net
Carbohydrate and Protein Systems (CNCPS) model
showed that leafy hybrids had a similar metabolisable
energy (ME) content and MS per cow and per tonne of
maize silage were not different. For dairy farmers growing
their own maize silage crop to feed to cows, the planting
of conventional hybrids will result in more MS and profit/
ha of maize grown than will the planting of leafy hybrids.
If maize silage is purchased on a cent/kg dry matter (DM)
basis, the small differences in nutritive content of leafy
and conventional hybrids will not affect MS production
or profit.
Keywords: dairy cows, leafy hybrids, maize silage yield,
nutritive value

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A series of in vitro incubations with kikuyu grass
(Pennisetum clandestinum), lucerne and six legumes
containing condensed tannins (CT) were undertaken to
evaluate this technique against in vivo trials in New
Zealand, measuring methane emissions. Published trials
have demonstrated a reduction in methane emissions
associated with CT and in one instance from kikuyu.
The incubations used fresh minced forage (equivalent to
0.5 g dry matter (DM)) and were carried out in 50 ml
sealed bottles containing buffer and rumen inoculum.
Gas was sampled through a septum to monitor volume
and composition throughout the 24h incubation.
Incubation for 24 h resulted in 2.4–6.6 % conversion of
DM to methane, and suggested CT concentrations
below about 8% of the DM can reduce methane
production without inhibiting fermentation rate. Higher
concentrations of CT (> 8%) were associated with a
lower rate of digestion. In common with in vivo trials,
CT concentration in forage DM was inversely related to
methane (adjusted R2 = 0.49; P = 0.01) and volatile fatty
acid (adjusted R2=0.86; P<0.001) production. Ash
concentration in forage DM was proportionally related
to methane (adjusted R2=0.56; P=0.005).
Keywords: ash, condensed tannins, in vitro incubation,
methane, rumen

The effect of grazing severity during winter on herbage regrowth and qualityJ.M. LEE, D. J. DONAGHY and J.R. ROCHE

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Grazing management is concerned with managing the
interactions between plants and animals. Two
management factors that require consideration are the
optimal grazing time and the effect of grazing severity on
subsequent regrowth. The objective of the current study
was to quantify the effect of grazing severity in winter
on leaf appearance r ate , herbage accumulation and quality,
and plant energy r eserves. Ten pasture areas were grazed
to two different residual masses (1260 ± 101 and 1868 ±
139 kg dry matter (DM)/ha, Severe and Lax, respectively)
over five consecutive days by dry dairy cows. Neither
growth rate (average 15 kg DM/ha/day), nor leaf
appearance rate (average 16 days/new leaf) differed
between treatments. As a result, herbage accumulated
over the 49-day regrowth period was similar between
grazing treatments (736 and 715 kg DM/ha for Severe
and Lax, respectively), although herbage mass when three
new leaves had emerged on regrowing tillers (third leaf
stage) was greater on the laxly grazed treatment. Perennial
ryegrass plants defoliated more severely displayed a trend
for lower levels of water-soluble carbohydrates (WSC)
than plants defoliated more laxly, but this difference had
disappeared by the third leaf stage of regrowth. Pasture
quality was improved in the severely defoliated treatment,
with higher digestibility, WSC and metabolisable energy
(ME) concentrations, and (ADF) lower acid and neutral
detergent fibre (NDF) concentrations.
Keywords: grazing sever ity, herbage production,
water-soluble carbohydrates

The effect of non-toxic endophytes in tall fescue on two major insect pestsA.J . POPAY, J.G. JENSEN and B.M. COOPER

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In a choice trial in a glasshouse, infection of tall fescue
with the endophyte AR542 significantly reduced
feeding by adult Argentine stem weevil (ASW) in the
cultivar J esup but not in Advance in comparison with the
same cultivars without endophyte. Paddocks of
Quantum infected with AR542 that were sampled on
two Northland farms consistently had fewer tillers
damaged by Argentine stem weevil than equivalent
paddocks of endophyte-free (Nil) tall fescue. In
comparison to Nil plants, AR542 in Jesup and Advance
had significantly fewer plants and tillers damaged by
adult black beetle in a glasshouse choice trial. Fewer
tillers were also damaged by adult black beetle in
Advance tall fescue infected with AR501 and AR502
than in Nil Advance in a small plot field trial at Kerikeri.
In a similar trial at Ruakura, the occurrence of adult
black beetle and signs of larval damage were high in
endophyte-free plots and considerably reduced in
endophyte-infected plots. It is concluded that the nontoxic
endophytes will lessen damage by black beetle and
ASW in a range of tall fescue cultivars and that this is
likely to contribute to increases in productivity and
persistence of this forage grass.
Keywords: Argentine stem weevil, black beetle, AR542
endophyte, Neotyphodium, tall fescue

The effect of two lime sources on short-term changes in soil pH under
Marlborough hill country pastureM.D. CRAIGHEAD

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The effect of fine slurried lime applied at 200 kg/ha on
soil pH at two depths was compared with 400 and
2500 kg/ha of local agricultural (ag) lime in the
presence and absence of sulphur (S) superphosphate
20, in Marlborough hill country for one year. In the
absence of fertiliser all lime treatments significantly
raised soil pH in the top 25 mm for the 355 days after
application. Initial responses declined from day 14 or
35 to day 138 before increasing at day 355. Fine lime
did not significantly alter pH in the 25-75 mm zone
until day 355. The low rate of ag lime significantly
raised pH in the 25-75 mm zone for the whole year.
The high rate of ag lime significantly increased pH in
the top 25 mm over the other lime treatments for the
355 days and over the fine lime treatment in the 25-75
mm zone from day 35. In the presence of fertiliser in
the top 25 mm, fine lime significantly increased pH at
day 14 only, and low ag lime at day 355 only. The high
rate of ag lime significantly increased pH over the
control from day 14 and over the other lime rates from
day 35. In the 25-75 mm zone the high rate of ag lime
significantly increased pH over the control and the low
ag lime rate from day 71 but was significantly better
than fine lime from day 35. It is likely that rain
immediately after application and higher than average
annual rainfall hastened the release of fine and
intermediate particles of lime. However provided lime
meets the accepted criteria for particle size distribution
and maximum size it is the rate of application which
dictates the magnitude of response. In Marlborough
hill country it was 43% cheaper to aerially apply 400
kg/ha of ag lime compared to 200 kg/ha of fine lime
with the added benefit of a greater residual effect
beyond one year.
Keywords: agricultural lime, fine lime, slurry, soil pH